In the past, as an input means for data in data processing, use has been made of the method of displaying data by characters and figures on the screen of a display such as a CRT of a computer and preparing data while engaged in a dialogue operation through the keyboard and a digitizer, mouse, light pen, track ball, joystick, or other input means. For example, much use is made of these in the fields of CAD for data processing by graphics and simulation.
In recent years, even in the fields of data processing and office automation, due to the excellence of their operability, there has been an increase in the use of operating systems and application software which perform processing with a dialogue type operation which requires the use of a pointing device in addition to a keyboard. For example, mention may be made of operations using windows and operations using icons.
In a pointing device, it is required that not only the usage environment be expanded and operation by conventional tabletop installation be made possible, but also, for portability, that the pointing device be able to be used with the computer on the lap or on one's palm. Therefore, there has been the problem that conventional mouses and digitizers and other pointing devices require a large installation space and are therefore unsuitable for portable computers.
Due to the need for portable computers to be light in weight, small in size, and low in power consumption, the pointing devices also have to be light in weight, small in size, and low in power consumption.
In the past, pointing devices have been separate from the computers and have been electrically connected to them by a cable etc. Included among these were mouses, track balls, etc. FIGS. 49A and 49B are an outside view and a sectional view of a typical mouse.
In the figures, 1001 is a mouse-shaped case. At the bottom of the inside of the case 1001 is provided a ball 1002 which can turn in any direction. Further, 1003 is a printed circuit board, on which printed circuit board 1003 are mounted two detectors 1004 and 1005 for detecting the rotation of the ball 1002 in two directions, an IC 1006, a switch 1007, etc. On the top of the case 1001 are provided keytops 1008 for depressing the switches 1007.
During use, the device is slid over the tabletop so as to rotate the ball 1002, whose rotation is then detected by the two detectors 1004 and 1005. This pointing information is sent to the computer through the IC 1006 and the cable 1009 so as to move the pointer or cursor on the display.
In the above-mentioned conventional mouse, the mouse is operated by sliding it over a flat surface, so there was the problem that a large space was required and the operability was not that good.
Further, a conventional joystick will be explained with reference to FIG. 50.
The figure is a perspective view of a conventional joystick. In actuality, only the lever projects out and the rest is accommodated in the case of the keyboard etc. In FIG. 50, if the operating member, that is, the lever 1021, is shifted in a predetermined direction, the X direction and Y direction transmission plates 1022 and 1023 cause the encoders 1024 and 1025 of those directions to operate, whereby the slant angle and direction of the lever 1021 are detected. The movement of the cursor etc. on the display is controlled based on the results of the detection. In this joystick, speed control is performed so that the speed of movement of the cursor changes in accordance with the slant angle of the lever 1021. When it is returned to the origin, where it is not slanted, the cursor stops. Further, the joystick is constructed so that when the lever is released it returns to the origin by the return spring 1026.
FIGS. 51A and 51B are a top view of FIG. 50 and a view of the movement of the cursor on the display corresponding to the operation of the joystick.
In FIG. 51A, when the lever 1021 is shifted from the origin O to the point A, as shown in FIG. 51B, the cursor 1028 moves to the position "P.sub.1 " on the display 1027. When the cursor 1028 is subsequently to be moved to the position "P.sub.3 ", the lever 1021 must first be returned to the origin O, then tilted to the point B at the left. The operator viewing the display, however, often moves the lever 1021 from the point A as is to the point C on impulse. If the lever is not returned to the origin O, however, the cursor 1028 moves at all times in direction and slant angle, so the cursor 1028 actually ends up moving to the position of "P.sub.2 ". Therefore, to move the cursor 1028 to the position of "P.sub.3 ", a further lever operation is required. If the operator is unfamiliar with this, an unnecessary operation easily occurs. Even when one is familiar with it and returns the lever to the origin O, the operation is troublesome.
Even with a track ball, usually the cursor is moved and stopped at the position corresponding to the absolute position of the ball, but control is sometimes performed so that the cursor continues moving by depressing a switch provided around the ball, for example, a pressure sensitive element, in accordance with the pressure on the same. This has a similar problem as with the above joystick.